Sosibius was the chief minister of Ptolemy IV Philopator, king of Egypt. Nothing is known of his origin or parentage, though he may have been a son of Sosibius of Tarentum; nor is there any account of how he rose to power. He is first attested immediately after the accession of Ptolemy IV in 221 BC, exercising great influence over the 22-year old king alongside Agathocles, the brother of Ptolemy IV's mistress Agathoclea. He remained a major force throughout the reign and helped ensure the smooth succession of Ptolemy V Epiphanes in 204 BC. After that he disappears from the record.
Gold octadrachm of Ptolemy IV Philopator (British Museum).
Tetradrachm of Ptolemy V Epiphanes, issued c. 200 BC.
Image: Cleomenes III
Image: Antiochos III coin
Ptolemy IV Philopator was the fourth pharaoh of Ptolemaic Egypt from 221 to 204 BC.
Gold octadrachm in the British Museum
Bronze bust of the 1st century BC, possibly depicting Queen Arsinoe III
Ptolemy IV depicted with Montu
Ptolemy IV depicted with a range of divine attributes on a gold octadrachm